Collect as many gems as you can before the timer runs out. Gathering the same color gem multiple times in a row gives you a score multiplier, make sure you use this to your advantage!Simply tap on any of the stones you see and Grinder will jump straight for it. Casual play is mostly meant for getting to know the game, once you feel comfortable with controls be sure to try TURBO MODE.Earn all 5 achievements and see how you compare to your friends on the leader-boards.